LanceDB C Bindings

This repository contains comprehensive C FFI bindings for LanceDB, allowing you to use all LanceDB functionality from C and C++ applications.

Project Structure

├── src/                    # Rust FFI implementation
│   ├── lib.rs              # Main library entry point
│   ├── connection.rs       # Connection management
│   ├── table.rs            # Table operations and data manipulation
│   ├── query.rs            # Complete query API implementation
│   ├── index.rs            # Index management
│   ├── error.rs            # Error handling and reporting
│   └── types.rs            # Type definitions and conversions
├── include/
│   └── lancedb.h           # Complete C header file with Arrow C ABI
├── examples/
│   ├── full.cpp            # C++ example using Arrow. Covering most of the API
│   └── simple.cpp          # C++ example using Arrow. Similar to rust/examples/simple.rs
├── tests/                  # C++ unit tests using Catch2
├── docs/                   # Documentation definitions
├── Cargo.toml              # Rust crate configuration
├── CMakeLists.txt          # CMake build configuration
└── README.md               # This file

Building

Prerequisites

• Rust toolchain (rustc, cargo)
• CMake (3.15 or later)
• C++ compiler with C++20 support (gcc, clang)
• Apache Arrow C++ library
• pkg-config

Quick Start

1. Build everything using CMake:

   mkdir -p build
   cd build
   cmake ..
   make

2. Run the examples:

   ./simple
   ./full

Manual Build Process

If you prefer to build manually:

1. Build the Rust library:

   cargo build --release

2. Compile the C++ simple example with Arrow:

   g++ -std=c++20 -Wall -Wextra -O2 \
       -I./include \
       $(pkg-config --cflags arrow) \
       -o examples/simple examples/simple.cpp \
       -L./target/release -llancedb \
       $(pkg-config --libs arrow) \
       -Wl,-rpath,./target/release

3. Run the example:

   ./examples/simple

Tests

Prerequisites

• Tests use the Catch2 framework. No need to install it as it will be fetched as part of the build process
• If valgrind is installed, some tests will run under valgrind and will fail on memory errors or definite memory leaks

Building and Running Tests

1. Build Tests

   mkdir -p build
   cd build
   cmake .. -DBUILD_TESTS=ON
   make

2. Run Tests

   ctest -j 6

Documentation

The LanceDB C API has comprehensive documentation generated from the header file comments.

Viewing Documentation Online

The documentation is automatically published to GitHub Pages on every push to main:

• URL: https://lancedb.github.io/lancedb-c/

Building Documentation Locally

1. Install documentation tools:

   • Install Doxygen (extracts API documentation from include/lancedb.h)
   • Install Sphinx and Breathe (generate HTML documentation):

   pip install -r docs/requirements.txt

2. Build the documentation:

   mkdir -p build
   cd build
   cmake .. -DBUILD_DOCS=ON
   make docs